PRODUCT REVIEW
Sunday Riley CEO 15% Vitamin C Brightening Serum
15% THD ascorbate at $85, a stable vitamin C derivative. Pleasant to use, priced like something with far stronger evidence behind it.
Key facts
Sunday Riley CEO 15% Vitamin C Brightening Serum at a glance.
THD ascorbate 15%
Key active
Lightweight, silky serum
Texture
Anyone who wants a vitamin C that never stings
Best for
$80–$85
Approximate price
1.01 oz
Size
$85.00
Price
Serum
Type
What is it?
Top things to know about Sunday Riley CEO 15% Vitamin C Brightening Serum
- Sunday Riley CEO 15% Vitamin C Brightening Serum is a light, silky serum in a dropper bottle, about $80 to $85, for anyone who wants a vitamin C that does not sting. It is a brightening serum, not a moisturizer, and nothing in it treats acne.
- The active is tetrahexyldecyl ascorbate at 15%, an oil-soluble vitamin C derivative shortened to THD ascorbate. Around it sit squalane, low-level glycolic acid, and tangerine and orange peel oils for scent. THD dissolves in oil rather than water, which is why the serum feels silky and does not sting on the way in.
Sunday Riley CEO 15% Vitamin C is genuinely pleasant and genuinely a derivative. THD ascorbate works at normal skin pH, so it never stings and never browns, but the evidence gap to L-ascorbic acid is wide. The dropper lets air in, and it carries glycolic acid and citrus peel oils. You are paying for the texture.
— Dr. Schwarz
Skin fit
Is it right for your skin?
Hyperpigmentation
A dark patch is melanin, made by pigment cells and handed to the skin cells around them. Vitamin C slows tyrosinase, the enzyme that starts melanin production, so less new pigment is made while old pigment sheds. Sunday Riley CEO 15% Vitamin C uses a derivative, so it works more gently and slowly than a stinging L-ascorbic acid serum.
Sun Damage
Ultraviolet light creates free radicals that break down collagen. An antioxidant takes the hit first. This is a comfortable way to get one on in the morning under sunscreen.
Dry Skin
THD ascorbate is oil-soluble, so the base is squalane rather than water and acid. Dry skin wears that far more easily than a low-pH vitamin C serum.
Texture
What it feels like on skin.
Serum
A light, silky serum that spreads thin and sinks in fast. The feel is a fair part of what you are paying for. It does not sting. THD ascorbate works at the skin's own pH, unlike pure vitamin C, which needs an acidic formula to get in. Tangerine and orange peel oils scent it, so it is not fragrance-free. It sits fine under sunscreen and makeup.
Alternatives
If this isn’t the right product for you
The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F
The same THD ascorbate at 20%, about $20, with no citrus oils and no glycolic acid.
Vanicream Vitamin C Serum
Also THD ascorbate at 5%, in an airless pump with ceramides and no fragrance. A lower dose, far cheaper.
Paula's Choice BOOST C15 Super Booster
15% L-ascorbic acid with vitamin E and ferulic acid, the better-evidenced form, fragrance-free and cheaper. It does sting.
Ingredients · Interactive
What’s in it, and where each ingredient works.
Full ingredient list · 27 ingredients, in label order. Click one.
The base the other ingredients are dissolved in. Most of it evaporates soon after the product goes on.
Vitamin E, an antioxidant. Here it mainly keeps the oils in the product from going rancid.
Another fatty alcohol. It softens skin and gives the product body.
A small humectant. It moves into the outer layer of skin and holds water there.
The preservative. It stops bacteria and mold from growing in the product.
How to use it
How to use it.
How to apply it
- How muchThree or four drops for the whole face. More does not do more.
- CarefulIt contains low-level glycolic acid and citrus peel oils. If your skin is reactive, start every other day, and not the week you start a retinoid.
What to pair it with
- LayeringIt goes on before anything thicker. Being oil-soluble, it sits better over a water-based serum than under one.
What to expect
- What to expectTone evens slowly, so give it eight to twelve weeks. Unlike pure vitamin C it will not turn brown.
Questions
Common questions.
Is Sunday Riley CEO 15% Vitamin C Brightening Serum pure vitamin C?
No. It is 15% THD ascorbate, a stable derivative.
Will Sunday Riley CEO 15% Vitamin C Brightening Serum sting?
The vitamin C will not, but the glycolic acid and citrus oils might.
Why does Sunday Riley CEO 15% Vitamin C Brightening Serum cost so much?
Largely the sensory experience; the active is cheaper elsewhere.
Is Sunday Riley CEO 15% Vitamin C Brightening Serum fragrance-free?
No. It contains citrus oils and fragrance components.
Does Sunday Riley CEO 15% Vitamin C Brightening Serum oxidize?
No. THD ascorbate is stable and will not turn brown.
References
Sources.
- 1. Topical Vitamin C and Its Derivatives in Cosmetic Science: Stability, Efficacy, and Formulation Strategies (https://brieflands.com/journals/jssc/articles/163798) — Peer-reviewed review confirming L-ascorbic acid requires a low acidic pH (2.0-3.5) and can irritate sensitive skin, while tetrahexyldecyl ascorbate is a lipophilic derivative that is stable at higher pH and penetrates skin more effectively, supporting the page's claims that THD is oil-soluble, works at normal skin pH, is stable, and does not sting like L-ascorbic acid. Link
- 2. Antioxidant Skincare Treatment for Hyperpigmented and Photodamaged Skin: Multi-Center, Open-Label, Cross-Seasonal Case Study (https://jcadonline.com/antioxidant-skincare-treatment-hyperpigmented-photodamaged-skin/) — Clinical study evaluating a 30% tetrahexyldecyl (THD) ascorbate serum that showed significant improvements in melanin, collagen, and hyperpigmentation, providing the supporting efficacy data referenced for THD ascorbate as a vitamin C derivative. Link
- 3. SUNDAY RILEY C.E.O. 15% Vitamin C Brightening Serum / Ulta Beauty (https://www.ulta.com/p/ceo-15-vitamin-c-brightening-serum-pimprod2007847) — Major retailer listing confirming the product's $85 price, 15% concentration, and THD ascorbate as an extremely stable, oil-soluble form of vitamin C. Link
- 4. What is Tetrahexyldecyl Ascorbate in Skincare? – Medik8 (https://www.medik8.com/pages/what-is-tetrahexyldecyl-ascorbate-in-skincare) — Clinical/educational source confirming THD ascorbate is a lipid-soluble, esterified vitamin C that is more stable than L-ascorbic acid, remains stable at skin-friendly pH (3-6.5), and is a gentler alternative without the stinging of L-ascorbic acid. Link